This invention relates to an apparatus for detecting one or more contours of an image formed on a screen.
Contour following apparatus have been proposed in the art for detecting an image contour. An image on a screen can be entered into an contour following apparatus by means of a scanner. The scanner scans pixels on the screen and produces pixel data each time it scans a pixel. The pixel data regarding the scanned pixels are successively stored in a memory to form a secondary image. The contour following apparatus extracts pixels which form the image contour and follows the contour forming pixels one by one based on the secondary image. One difficulty associated with such a conventional contour following apparatus is that the used memory should have a great number of memory sections for storing pixel data in number equal to the number of the pixels located on the screen.